The present invention relates to an arrangement forming part of a shock absorber and intended to produce distinct longitudinal displacement positions of an element as a function of longitudinal displacements of a member, such as a screw, for example. In this, the displacement directions of the member and/or the screw diverge and may differ by 45-90xc2x0, for example. Displacement of the element is furthermore designed to occur against the action of a force on the element.
Producing displacements of such an element by means of the action of a member is already known in shock absorbers. Thus the facility for manual, external adjustment of the shock absorber bleed by means of a member, the actuation of which displaces the element thereby acting on the restrictor, is known in shock absorbers. Reference might be made here to the xc3x96hlins brand shock absorber, type 46 PRC, available on the general market. There is a desire in this context to be able to obtain distinct positions and possibly clicking noise effects at the transitions between the various actuation or adjustment positions. In order to achieve this it has hitherto been proposed to distinguish the element actuating function itself from the function of producing distinct positions and possibly clicking noise effects.
In the case of shock absorbers there is often a problem of reconciling the demand for space with that of functionality. For example, there is the problem of being able to perform adjustment functions on shock absorbers externally, given the pressing need to enclose or build the shock absorber into the chassis. Thus, for example, there may be problems in implementing a desired adjustment function for the restrictor or bleed in spaces where there are difficulties in applying or arranging actuators for the adjustment. The need for a compact and efficiently functioning but nevertheless relatively simple construction is paramount. The invention is intended to solve this and other problems.
When externally adjusting the bleed, for example, there is a need to be able to carry out adjustments in the form of distinct adjustment positions, which at least in certain cases must also be additionally capable of producing noise effects (so-called clicking noises) at the transition between the various positions. The distinct positions must also be precise and be capable of meeting existing accuracy requirements for the adjustment. The arrangement must also be such that it can be adapted to different methods of incorporating the shock absorber into the chassis without neglecting the accuracy requirement. There is a need to make the adjusting arrangement technically simple with only a few parts, and moreover non-critical. If turning tools/screwdrivers are used, the access must be clear and distinct. It must be possible to make the element and/or its associated parts of aluminum, steel, magnesium or alloy and it must not be subject to undue mechanical wear by the actuating arrangement. In one embodiment the arrangement must be compact in its diameter and cross-sectional dimensions. In addition, there must be sealing to prevent the ingress of water and dirt. Thus, for example, the arrangement must prevent water and cleaning agents getting in during high-pressure washing. The invention is also intended to solve these problems.
The arrangement according to the invention is essentially characterized in that the member or the screw is designed with a tapered or inclined surface, that the element or a part related thereto is pressed against the surface by the said force and that interacting sections of the surface and the element, or of the part, are designed with structures that produce the said distinct longitudinal displacement positions of the element when acted upon by the member.
In a preferred embodiment, the member and the element are arranged in connection with an end attachment on the shock absorber. The element or the part can thereby extend into the attachment and be arranged so that it can be acted upon by the member or the screw for manual, external adjustment of a restrictor (bleed) through actuation, such as turning, by means of a tool/knob/screwdriver, via a recess in the end attachment. In the said preferred embodiments the member or the screw comprises a front threaded part, the thread of which interacts with a corresponding thread in or inside the end attachment. In addition, the member or the screw has a second part of conical design with a structure comprising depressions extending side by side and in the main longitudinal direction of the surface, and ridges arranged between these. In one embodiment the depressions have an essentially curved cross-section and may extend along the main parts of the longitudinal extent of the conical or inclined surface. The member or the screw preferably also has a third part designed to carry a seal, such as an O-ring, that provides sealing against the wall in the recess of the end-piece. The member or the screw may also have a fourth part in the form of an end part, via which the member or the screw can be actuated by means of a tool, such as a turning tool or integral knob.
The end attachment may be arranged with a high degree of enclosure, in view of the fact that access to the member, the element or the part can be effected via a lateral recess in the end attachment. The recess may be freely selected in respect of its orientation and location around the circumference of the end attachment. At its end capable of interacting with the structure of the member, the element or the part is designed with a structure in the form of a sphere or spherical shell, the shape of which is matched to the structure of the surface in order to minimize the surface pressure, thereby reducing wear. Where the member is moved to each distinct position by a turning action, the conical or inclined surface is displaceable in relation to the end of the element or the part, whilst the element is arranged so that it can be pressed upwards or outwards against the action of the force referred to in the introductory part by means of the ridge between the depression, which releases the element to the succeeding depression that the element must occupy owing to the turning action. The ridges are formed so that they narrow towards that section of the conical or inclined surface having the smaller diameter, that is to say the depressions are designed with essentially the same width over their entire extent on the conical or inclined surface.
The above-mentioned proposals provide a number of advantages. The arrangement is unambiguous from the point of view of actuation, whilst the various functions can be incorporated into a single part, which can easily be designed to reproduce the precise requirements for adjustment and distinctiveness. The arrangement also provides a simple way of excluding any dirt particles, which are prevented from getting into the recess in the end attachment and adversely affecting the actuation functions for the restrictor or bleed in question. The invention can also be used in connection with other types of adjustments, in which a displaceable element is required having distinct displacement positions and stipulated accuracy requirements. The ability to select the location of the recess around the circumference of the end attachment is also a great advantage where the function is to be incorporated into different types of shock absorber installations in the chassis. The arrangement also provides an excellent overview of the tool application. The member can be manufactured from steel or other suitable material. The said part can be made of correspondingly durable material while the actuating rod itself, due to functional reasons of the bleed, can be manufactured from aluminum or other corresponding material. The conical or inclined surface may be formed in some other way, for example by means of inclined parts or fins that are held together by rings, welds etc. at their ends, the said parts or fins being formed with curved or gently sweeping surfaces in their sections capable of interacting with the element.